1. Field of the Invention
This invention relates to the display of an image or images (such as an audio image, a video image, or an audiovisual image) over a period of time and, in particular, to systems and methods for pausing an image display, then resuming the image display in a manner that maintains the continuity of the image display while reducing or eliminating additional time required to finish viewing the entire image display beyond the time that would have been required without the pause.
2. Related Art
During standard operation in many display environments, one or more images are displayed over a period of time automatically, independent of action by an observer of the displayed images. (Herein, "image" can include any sensory stimulus, such as, for example, video images and audio images.) Typically, the image display changes over time, but this need not necessarily be the case. The display of an audiovisual program on a television, an audio program on a radio, an audio recording on an audio cassette or compact disc, or an audiovisual recording on a video cassette or compact disc are just a few examples of the display of a time-varying image or images over a period of time. An image generated from monitoring a "site" (including physical sites and virtual sites, the latter including aural, graphical and textual "sites") is an example of an image generated over a period of time that may not vary over the period of time.
It is desirable for an observer of such a time-varying, automatically displayed image to be able to pause the display of the image. Previously, this has been done by halting the display when the observer supplies an appropriate instruction, then beginning the display again, at the point at which the display was halted, when the observer supplies another appropriate instruction.
For pre-recorded images (e.g., the audio and/or video on a video cassette or a video compact disc, or the audio on an audio cassette tape or an audio compact disc), the implementation of such pausing is straightforward, since all of the display data comprising the complete image is already stored on a storage medium and can be accessed as desired. Such capability to pause the display of pre-recorded images has been implemented in most consumer electronics equipment (e.g., video cassette recorders, compact disc players, cassette tape players) that is used to display pre-recorded images.
A difficulty is encountered in implementing the above-described conventional pausing method for images that are not pre-recorded, but, rather, are represented by display data that is only momentarily available to the display system for generation of an image display (as is the case, for example, with the broadcast of a television or radio program). Display data acquired by the display system during the pause cannot be immediately displayed, yet if this display data is discarded, part of the image can't be displayed. In many situations, this is undesirable or unacceptable.
This problem might be remedied by enabling the display system to store all of the display data acquired after beginning the pause, then resuming the display after all of the remaining display data of the image has been stored. However, this approach is undesirable because it is inflexible (the specification of any pause terminates the display of the image until all of the display data of the image has been acquired, e.g., until the television or radio broadcast is over) and because the display of the image extends for an undesirably long time (e.g., a pause early in a broadcast of a baseball game would mean that the end of the game would not be seen or heard until a couple of hours after the game was over).
Another possibility for addressing this problem is to store the display data acquired during the pause, then, when the pause is over, display the stored display data while simultaneously storing newly acquired display data. Such simultaneous displaying of previously stored data while storing newly acquired data would continue until all of the display data of the image has been acquired and displayed. Additional pauses cause the display to stop while even more data is stored. However, while this approach permits somewhat more flexibility--the observer can control when the display begins again by terminating a pause--it still causes the amount of time required to observe an image to increase by the total duration of the pauses. This may be undesirable or unacceptable if the observer has, or only desires to allot, a limited amount of time to view the display.
An approach to pausing the display of a time-varying image that overcomes the limitations of the above-discussed methods is desirable.